From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f50.google.com (mail-ej1-f50.google.com [209.85.218.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B5DA3FC0 for ; Wed, 25 Aug 2021 04:35:11 +0000 (UTC) Received: by mail-ej1-f50.google.com with SMTP id a25so22132542ejv.6 for ; Tue, 24 Aug 2021 21:35:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=jnVkSyJgN3E1sDFilQH189RfendGOGfI1/ufZRZKyB0=; b=Cco65m4HBzBTv5b8p+0hDWptfNctJ7xmLI2VkvaRSCIRXeS2lcwfYCJx1TakW/zrB/ vBm+AhQNFZuLtPcsAieUcgf+06flF3tDmudZ+wNG/LwyweO6IgiIga+cK2VEv6kVphZa bWwVskoq6mgw31zYgX9ocyPqW8jPOMtp1H1Q2dsd2fRu9mGHy8UTESBoRmy9Pa1CltWT AyBHLW2Y4zVpLep+696g9UTNSo27PvANqWC5NrMZ1tKEwFRYB4r2/Fbuz7CQ4kQLSwNh I168HLpgNZdTkp5GqGy7Rn3XBehwH6nMCvQgUrdIXkOV2AU5usEx2gfJnr691a10XB7L XaVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=jnVkSyJgN3E1sDFilQH189RfendGOGfI1/ufZRZKyB0=; b=WYGH/4K4X1tMGAxg+1D28o1WrOkS95J6pAef1hRK3zr/ersXUxPhHdhv1a9QEyq3EK X7XA8NFfuHPDSifJ1IpOYNuvRRYz4LP17DpPeIJV+IUh5+oDKNiYPuXsd5gX3mzszXh2 VYreO0M28Bl5ChV7ozm7BfmSwvz8pmQ26AWqDhWc4G2ef/V9VVU2wTkogJpYWrhOJoiZ UVXAnA5rV8DjvRuA/2Qi1QAOf7+HpOIGTiW3fF92wJnoqoLc6p9gBu7iw5EN0oWyoBQd 9BSvhhDf/HZNa28O7j/30HsbkTaY5e+phBcpMQA5TI7HqZY2K2rhHVzIey/Lowzua8n1 +VnQ== X-Gm-Message-State: AOAM533OdF7p4+uUvwWr59vINiB5+kOwdvOLSlofj2RE9iaGn5HNEXFO of5IXE/h3pJ8UffnQphKPBQ= X-Google-Smtp-Source: ABdhPJwUciuGXzKcuga0wgY2pqKDLFo5GDsUCC35UCs1jFKLv6eiNgf6mXYx4rZhcerDanUrAdtxrw== X-Received: by 2002:a17:906:b183:: with SMTP id w3mr30349862ejy.394.1629866110430; Tue, 24 Aug 2021 21:35:10 -0700 (PDT) Received: from localhost.localdomain (host-79-22-100-164.retail.telecomitalia.it. [79.22.100.164]) by smtp.gmail.com with ESMTPSA id v12sm10292649ejq.36.2021.08.24.21.35.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Aug 2021 21:35:09 -0700 (PDT) From: "Fabio M. De Francesco" To: Larry.Finger@lwfinger.net, phil@philpotter.co.uk, gregkh@linuxfoundation.org, straube.linux@gmail.com, Pavel Skripkin Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 4/6] staging: r8188eu: add error handling of rtw_read16 Date: Wed, 25 Aug 2021 06:35:08 +0200 Message-ID: <1665728.ljvk3MsED4@localhost.localdomain> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" On Tuesday, August 24, 2021 9:27:35 AM CEST Pavel Skripkin wrote: > _rtw_read16 function can fail in case of usb transfer failure. But > previous function prototype wasn't designed to return an error to > caller. It can cause a lot uninit value bugs all across the driver code, > since rtw_read16() returns local stack variable to caller. > > Fix it by changing the prototype of this function. Now it returns an > int: 0 on success, negative error value on failure and callers should pass > the pointer to storage location for register value. > > Signed-off-by: Pavel Skripkin > > [...] > > -static u16 usb_read16(struct intf_hdl *pintfhdl, u32 addr) > +static int usb_read16(struct intf_hdl *pintfhdl, u32 addr, u16 *data) > { > u8 requesttype; > u16 wvalue; > u16 len; > - __le32 data; > + int res; > + __le32 tmp; > + > + if (WARN_ON(unlikely(!data))) > + return -EINVAL; > > requesttype = 0x01;/* read_in */ > wvalue = (u16)(addr & 0x0000ffff); > len = 2; > - usbctrl_vendorreq(pintfhdl, wvalue, &data, len, requesttype); > + res = usbctrl_vendorreq(pintfhdl, wvalue, &tmp, len, requesttype); > + if (res < 0) { > + dev_err(dvobj_to_dev(pintfhdl->pintf_dev), "Failed to read 16 bytes: %d\n", res); > + return res; > + } else if (res != len) { Dear Pavel, Please note that if and when my patch "Use usb_control_msg_recv / send () in usbctrl_vendorreq ()" will be merged, "if (res! = len)" will always evaluate 'true' and usb_read16 () will always return -EIO even if usbctrl_vendorreq () succeeds. > + dev_err(dvobj_to_dev(pintfhdl->pintf_dev), > + "Failed to read 16 bytes, could read only %d bytes\n", res); > + return -EIO; > + } > > - return (u16)(le32_to_cpu(data) & 0xffff); > + *data = le32_to_cpu(tmp) & 0xffff; > + > + return 0; > } [...] Regards, Fabio